Diaphragm support



Sept. 20, 1960 w. L. CARLVSON, JR 2,953,166

DIAPHRAGM SUPPORT Filed Nov. 22, 1957 INVENTOR.

WILLIAM L. CARLSON, JR.

ATTORNEY United States Patent "ice DIAPHRAGM sUPronT William L. Carlson,Jr., Bloomington, Minn., assignor to Minneapolis-Honeywell RegulatorCompany, Minneapolis, Minn., a corporation of Delaware Filed Nov. 22,1957, Ser. No. 698,084

1 Claim. (Cl. 137--788) The present invention is directed to a type ofdiaphragm support for use in hydraulic actuators, and more specificallyis directed to a support means for use in an actuator which may beutilized with highly corrosive conductive fluids such as conductiveliquid metals.

In recent years numerous hydraulic systems have been developed utilizingconductive fluids such as mercury, so dium, potassium, andsodium-potassium mixtures. While most of the systems have utilized theconductive liquid metals as cooling media in heat transfer systems otherapplications have also arisen. An example of such a system is thecombination of a pump and a plurality of Variable volume chambers whichare used to obtain motion when a conductive liquid metal is moved. Dueto the corrosive nature of the sodium and potassium types of conductiveliquid metals it has been necessary to engineer and build hydraulicactuators which are hermetically sealed and which have adequate safetyfeatures in case of a rupture of one of the hermetically sealedchambers. In order to use a hydraulic actuator which is filled, forexample, with a sodium-potassium mixture in residential and commercialapplications it is necessary to build an actuator which can adequatelycontain the corrosive fluid under all operating conditions. It is alsonecessary to supply a unit which has mechanical practicability and whichis further economical to build.

It is the object of the present invention to disclose a diaphragmsupport for use with an actuator which is capable of handling highlycorrosive types of liquid metals and other fluids in a hermeticallysealed system.

A further object is to provide a diaphragm support for an actuator whichutilizes a neutral fluid between the diaphragm and a bellows chamber asa leak resistant safety feature.

Yet another object of the present invention is to dis close a diaphragmsupport arrangement whereby the bight of the diaphragm is continuouslysupported so that the pressures applied to the active side of the unitcan be safely retained regardless of the operating pressure.

These and other objects will become apparent when the three sheets ofdrawing accompanying the present specification are considered, wherein:

Figure 1 is a cross section of a diaphragm support means utilizing tworelatively movable rings, and

Figure 2. is an isometric View of the two rings used in Figure 1. I

In Figure 1, a diaphragm 24 lays across the top 83 of a piston 82. Acylinder 22 is provided having a bottom plate 34. An output shaft 31passes through the bottom plate 34 and attaches to the top 83 ofcylinder 82. A coil spring 32 biases the piston 82 to its uppermostposition, as shown, and is coiled around the shaft 31. The bottom 36 ofbight 35 of the diaphragm 24 is supported on a cylindrical member 84made of an appropriate plastic material. The member 84 has fourdominantly projecting teeth 85 whose slope 86 is selected to give themember 84 a particular rate of linear movement when rotated over theteeth 87 of the member 88. The member 88 is a cylindrical plastic memberhaving the teeth 87 cut in its upper surface and the slope of the teethPatented Sept. 20, 1960 87 is the same as the slope of the teeth 85. Themember 88 is placed inside of cylinder 22 and is attached by anyconvenient method to the bottom plate 34. It is attached in such amanner that it can not rotate or be moved and its inner surface 89 actsas a guide for the cylinder 82. The member 84 further has two slots 99cut into two of the teeth on opposite sides of the member 84. Theseslots are engaged by a pin 91 which is attached to the outer surface ofpiston 82.

The shaft 31 is fixed against rotation at the load to which it isattached (not shown) and thereby the pin 91 moves in a linear directionwith the piston 82. Since the pin 91 rides in slot and moves in a linearmanner only, it becomes apparent that the member 84 is caused to rotateas the pin is moved relative to it. When the diaphragm 24 is exposed topressure and the piston 82 moves, the pin 91 moves in the groove 90causing the block member 84 to rotate. Since the block 84 has slopedteeth 85 which mate with teeth 87 of member 88, the block 84 rotates andslides along that slope. It is obvious therefore that the member 84rides up and down in a parallel relationship to the movement of thepiston 82. By the proper selection of the slope 86 of teeth 85 and ofteeth 87 it is possible to give the member 84 a movement which isone-half the linear rate of the movement of pistons 82. It can thus beseen by properly selecting the dimensions and materials of the members84 and 88 it is possible to yield a diaphragm support member whichcontinuously supports the bottom 36 of the bight 35, to in turn prm videthe safety required of the overall actuator.

The present application has been illustrative only of one of the manypossible ways in which the bottom 36 of bight 35 can be supportedcontinuously where a diaphragm 24 is used to seal a fluid tight chamberagainst a moving piston or cylinder. With this arrangement it ispossible to build units which are hermetically sealed and capable ofhandling corrosive fluids such as liquid metals and which furtherprovides a double safety chamber having the complete safety and strengthrequired of it in the commercial world. It is obvious that many methodscould be utilized to support the bottom 36 of bight 35 within theteaching disclosed and the applicant has provided an example only of onepreferred embodiment. The applicant wishes to be limited in no way otherthan by the scope of the appended claim.

I claim as my invention:

In a device of the class described: cylinder means having a movableloose fitting piston means therein; pin means attached to said pistonmeans; a diaphragm member sealing said cylinder means into two sections;said diaphragm member riding against said piston means and having abight separating said piston and cylinder means; an annular bightsupport ring having a plurality of sloped teeth on a side opposite saidbight and said ring in contact with said bight between said piston andcylinder means; a bottom ring in line with said support ring; saidbottom ring having sloping teeth mating with said support ring teeth;one said ring having slot means; and said pin means engaging said slotmeans to cause one said ring to rotate as said piston means moves; saidrings rotating relative to each other and moving towards each other atone half the lineal rate of movement of the piston means allowing saidmating teeth to slide relative to each other and thereby continuouslysupport said diaphragm member.

Hoskins Mar. 4, 1952 Ludowici Oct. 26, 1954

